Landcare Research - Manaaki Whenua

Landcare-Research -Manaaki Whenua

Sellaphora styxii P.M.Novis, J.Braidwood & C.Kilroy

Sellaphora styxii

Type slide

CHR 618419, Styx River, Christchurch, New Zealand (lat. 43°27.800, long. 172°36.213), periphyton, P.M. Novis and J. Braidwood, 4 November 2009 (cleaned frustules made from culture LCR-S: 19:1:1).

Institution holding the type material

Publication

Known distribution

Styx River, Christchurch, New Zealand.

Etymology

After the Styx River, the site of its discovery.

Description

Frustules elliptical in valve view, 5.0-8.0 µm long, 2.5-2.9 µm wide, with rounded poles, biraphid.  Live cells usually contain a single H-shaped plastid, but this sometimes fragments to give two parietal plastids appressed to each valve margin.  Valve face planar and curved at the margins.  Striae radiate, uniseriate or (more commonly towards the poles) biseriate, 22-25 in 10 µm.  Central area "bow tie"-shaped, less obviously in smaller cells.  Areolae round, variable in size and spacing, not aligned longitudinally.  Transapical ribs not deflected; groove parallel to the raphe absent.  Raphe central, with sinuous external fissures; central endings deflected towards primary side; apical endings hooked towards the secondary side.  The apical raphe endings are curved in opposite directions on the hypovalve and epivalve.  Transapical bars (as in S. pupula (Kütz.) Mereschk.) absent.  

Notes

Funding from TFBIS (Terrestrial and Freshwater Biodiversity Information System), administered by the New Zealand Department of Conservation, is gratefully acknowledged.

Reference

Novis PM, Braidwood J, Kilroy C 2012. Small diatoms (Bacillariophyta) in cultures from the Styx River, New Zealand, including descriptions of three new species. Phytotaxa 64: 11–45.